sluggish acceleration

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SLEDBOY2K
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  • 39 POSTS
Engine has had new head gasket replaced and head checked. Engine starts and idles fine but is fairly sluggish on acceleration. New plugs (less than 10 miles) show lots of carbon on the back cylinder bank and pretty normal, light colored on the front bank. Catalytic converter is more than half plugged. EGR looks good, new cap and rotor, coil pack tested with ohm meter. Back oxygen sensor is black and carbony, front one is whitish(most likely from burnt engine coolant due to head gasket). Would o2 sensor in rear bank cause such rich conditions and power loss?
Oct 10, 2010 at 3:25 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Hi sledboy2k, Welcome to 2carpros and TY for the donation

Probable causes of an engine running rich are as follows:

1.Excessive fuel pressure can be cause by restricted fuel return line or defective fuel pressure regulator.
2.Defective Oxygen Sensors.
3.Leaking injectors and fuel pressure regulator.
4.Coolant temperature sensor out of calibration.
5.Restricted air intake system.
Oct 10, 2010 at 9:21 PM
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